"There are no words to explain how we feel about them and all the staff at the hospital.

"They have saved his life.

"It's lovely he's back home and we can be a family again."

Albert was born with Hypoplastic left heart syndrome, where the left side of the heart does not form properly.

At a week old, surgeons at Glenfield Hospital operated on his heart and he had further open heart surgery nine months later.

Doctors were pleased with his progress and were not due to see him until later this year.

But a month ago, Albert suddenly collapsed at home after suffering chest pains.

Full time mother Mrs Tansey said: "The night before we had been to a party in aid of the charity we set up after Albert's diagnosis. Some of his doctors were there and everyone kept saying how good he looked.

"The following morning, I was sat talking to a friend in the kitchen when his brother came in and said Albert didn't feel very well.

"He was grey and sweating. He kept saying: 'it hurts' and when I asked where he pointed to his heart."

His terrified parents immediately called for an ambulance and he was rushed to Leicester Royal Infirmary Hospital.

The youngster was connected to a heart monitor and the readings were sent to Albert's team of doctors at Glenfield.

They spotted 'something they didn't like' and he was quickly transferred to the intensive care unit at Glenfield.

Adam, 38, an insurance broker, said: "Within an hour of getting there they realised he had heart failure.

"We were told the heart gives out a chemical when you are having a heart attack. A nurse had the reading on her hand and showed the doctors.

"They were in disbelief. It's so rare for a child to have a heart attack."

Albert was given shots of clot busting drugs while doctors battled to save him.

That evening, his parents were given the devastating news that he may not survive and if he did, he may need a heart transplant.

Over the next couple of days, they faced an agonising wait as doctors tried to stabilise his heart.

Mrs Tansey said: "It was awful. He was going through hell. All we could do was sit by his bed and hope for a miracle.

"You would do anything for your child just to make them better.

"The doctors then had a discussion and told us they wanted to try putting some dye in Albert's heart to see if there was a blockage.

"We knew that there were huge risks to any intervention because Albert's heart function was so poor, and therefore anaesthetic was not really ideal, but we felt the only option was to have hope, be positive and give him the best chance of the best quality of life."

Albert's surgeon Mr Peek then came to his parents to say they had found a blood clot and asked for their permission to remove it.

Mr Tansey said: "We didn't really hesitate. We have ultimate respect and huge amount of confidence in the team who look after Albert so when we met with Mr Peek it felt right to go with the procedure as success would give Albert the best chance."

Luckily, the adult cardiac team is based alongside the children's unit and Dr Albert Alahmar, a consultant adult interventional cardiologist, was asked to be on hand.

Although it had never been done before on a child, it was agreed the best option was to perform a percutaneous coronary intervention, where the clot is sucked out of the heart.

Mr Tansey said: "About 25 minutes later, another doctor came back with the blood clot in his hand. He said: 'We've done it. It's amazing'.

"Then the room was full of doctors. There was an all round feeling of relief and excitement.

"Not just for what this has done for Albert and the hope it gave to him, but what it meant for the future.

"We met Dr Alahmar the next day and he told us how excited he was about this. How paediatric cardiologists would learn from this and it could help others.

"It felt special that our Albert had been part of something so big, and his life will go onto help others in the future."

Albert's heart function immediately improved and after 11 days in hospital he was allowed home.

It is still not known what caused the clot but he will continue to be monitored regularly and will have to be on medication for the rest of his life.

The couple, who also have four other children, Charlie, 16, George, 14, Emily, 12 and six-year-old Fred, are campaigning to keep the children's cardiac care unit open.

Under current plans, it is due to close and patients from the East Midlands will be transferred to Birmingham Children's Hospital, Newcastle or London where there may not be an adult unit.

Dr Albert Alahmar, consultant adult interventional cardiologist at Glenfield Hospital, said: "The procedure is called percutaneous coronary intervention, where the clot is removed to unblock the artery and allow the blood to flow back again through it.

"As far as I and my colleagues are concerned, this has never been done on a child as heart attacks in children are rare. This is unchartered territory.

"It is a risky procedure because failure to aspirate the clot under general anaesthesia may result in death. It is more likely to be fatal for children with a condition like Albert's because he has a single chamber, where any damage by a heart attack is magnified.

"It really is remarkable.

"At Glenfield Hospital, we have an excellent relationship between the adult and paediatric cardiologists, allowing such rare cases to be treated exceptionally well."

Dr Frances Bu'Lock, Albert's paediatric cardiology consultant, said she was very pleased with Albert's progress.

She said: "His heart function improved dramatically by the end of the procedure.

"It's not back to normal yet but there is a very good chance he will get better for his third operation in a year's time.

"It's great to see him running about and playing."

For more information about Hypoplastic left heart syndrome and the campaign, please visit www.keepthebeat.co.uk